Connector Design Selection for Modular Forest Bridge Using Finite Element Analysis

Abstract

Forest harvesting in Malaysia is currently being carried out deep inside the forest where accessibility is the main problem. Under the current logging road specification, temporary bridges are built with log stringer for temporary usage and are removed or left to deteriorate at the end of the use period. This situation leads to a problem to whoever needs to cross the stream for official or personal purposes. This road is customarily used only for a short period with a prolonged usage cycle, and this leads the management to close these roads whenever there are no logging activities. Most of the time upon completion of logging activities, these temporary bridges are not maintained and will deteriorate and collapse due to the high velocity of water flow, erosion, and sedimentation. Modular and mobile concepts of the bridge are recommended for easy transportation, installation, and removal for reuse at multiple sites. This modular mobile forest bridge consists of the segmented timber beams which are joined by aluminium connector. Therefore the critical part of this structure is at the joint where failure might occur when the loading is applied. Five connector designs had been recognised to join the segmented timber beams. Finite element analysis (FEA) was used under static stress analysis with five different load cases to carry out the simulation. Modulus of resilience was calculated to determine the capability of the material to store energy under the deflection. Deflection analysis and volume of connectors were also analysed for result comparison.